Symphony in C, Allegro
by island.dreamer17
Summary: <html><head></head>Their lives moved together like a piece of music: speeding up, slowing down, always changing. She analyzed music; he analyzed criminals. He knew nothing about music, yet he was intrigued by her. Colby/OC.</html>


**Welcome to Symphony in C, "Math," Part 1: Allegro!  
>It's been a long time since I've posted anything on here, but I've been working on this story for a long time and I wanted to share it. I have bits and pieces of this series written, and they're all half-finished. I'm going to try to get them all prettied up and posted as quickly as I can, but I can't guarantee too much. My bits and pieces are also not necessarily in order, so that's a problem too LOL. <strong>

**Here's how this is going to go, if you're wondering:  
>This story will follow the standard movement ordering of a symphony. The first movement is called Allegro. Next is Adagio, then Scherzo, and Rondo. Each movement will characterize a phase of Caitlin and Colby's relationship. I've also planned an Intermezzo, which plot-wise will fit between the penultimate and last chapters of the Rondo.<strong>

I read a story a while back of Colby falling in love with Charlie and Don's little sister. I liked the idea, so I ran with it. This first part is story-like, but it will become more like a series of one-shots once the ColbyxOC pairing is established.

**This takes place mid- to late-season 2. **

**DISCLAIMER: I don't own anything except Caitlin. **

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><p>Part I: Allegro<p>

_con moto (with motion)  
><em>"Do you know where I can find Professor Eppes's office?" the young woman asked a passing student.

He pointed. "It's like the second or third door on the right, around the corner there," he said. "His door's usually open."

"Thanks." She headed down the hall, looking for the nameplate that would indicate she was at the right room. She stuck her head inside, seeing the unmistakable figure of Charlie Eppes in the room, and knocked on the door before stepping inside the large room.

"I'll be with you in just a minute." The professor's curly head was bent over some papers, scribbling furiously as the woman shut the door behind her. His scribbling slowed, then stopped, and he looked up. "Caity!" he exclaimed.

Caitlin smiled. "Surprise," she said.

"What are you doing here?" Charlie asked his little sister. "I thought you were looking for a job."

Caitlin spread her arms, and replied, "You're looking at it."

"I didn't think CalSci had a musicology department," Charlie told her, puzzled. Caitlin had been the only Eppes child to inherit her mother's musical talents, and had gotten her degrees in musicology and math, among other things.

"They didn't," Caitlin said. "But they were impressed with my Gallatin degree, and said they were looking for a little diversity in their curriculum. They've asked me to head up a brand-new musicology department, developing curriculum for a music theory undergrad major and a math musicology grad program, as well as adding some elective music classes for undergraduates. The department won't officially get off the ground for a couple more years—we have to set curriculum and requirements, and they may have to hire a couple of new professors. But they think math musicology is an interesting field, and they want to be on the forefront of it."

"That's so exciting!" Charlie congratulated her. "And you get to join the rest of the family here in LA," he added with a smile.

Caitlin nodded. "Yeah, that was a bonus."

"Did you get an apartment already?" Charlie asked.

Caitlin shook her head. "No. I found out I got the job about a month ago, and I was supposed to come out in the fall to start preparations for next schoolyear. I wanted to surprise you guys. But then last weekend I got a call from the curriculum committee asking if I'd be willing to start teaching some undergrad math courses for the fall just to get my feet wet here, and start teaching some basic music theory courses starting next semester so that if we get the major program up and running in time to offer it next year, students will be able to jump right in. So I packed up my things, rented a U-Haul, and got in about two hours ago. They showed me my office, gave me my ID and my parking pass, and now here I am."

Charlie looked at his sister incredulously. "Where were you this morning?" he asked.

"Southern Utah?" Caitlin had a feeling she was getting into some hot water with her brother.

Charlie looked at his watch. "Caitlin Rose," he scolded. "You should be at home, resting."

"It was only eight hours!" Caitlin protested. "That's less than I have been driving this whole week."

"Exactly!" Charlie argued. "Listen, I have to get this over to Don at the FBI so they can hopefully close this case tonight, and you're coming with me. Then I'm taking you home, no questions asked. I'll get Don or somebody to come drive your U-Haul home."

"You work for Don now?" Caitlin asked, eyeing her brother. "He must be rubbing off on you. You're never this assertive with me."

Charlie looked at his little sister. "Caity," he began, softer this time, "you've been driving all day and all the days before this. I know it's going to take physical restraint to get you to relax, and if I have to get Don to handcuff you to your bed, I'll do it." He cracked a wry grin. "Now, I really have to get this info to the FBI. Are you coming, or not?"

Caitlin rolled her eyes at her brother. "Yes, I'm coming."

Half an hour later, Charlie rushed into the FBI bullpen, Caitlin trying to keep up with him. Her exhaustion was setting in, though, and she was quickly falling behind.

She slowed down to a walk, taking in the sight before her. She'd never been in the FBI office where her oldest brother worked, and she wanted to look around. She watched Charlie disappear into a room with Don and several other people whom she assumed he worked with, and slowly made her way over.

Caitlin got to the doorway just as the two other men left the room. "Is it safe to come in?" she asked Charlie, who was gathering up his things while making small talk with Don.

Don looked up. "Caity?" he asked, unsure of whether his little sister really was standing there. "What are you doing here?"

"He made me come," Caitlin pointed to Charlie. At Don's raised eyebrow, she explicated, "I'm moving back to LA."

"That's awesome!" Don hugged his sister. "I'd love to catch up with you, sis, but I've got to go. David and Colby are getting the tactical teams and SWAT together and I'm supposed to meet them in the armory. But I'll see you at home later?"

"Did you all move in together with Dad or something while I was gone?" Caitlin asked.

Charlie shook his head. "No. Don just doesn't really spend time in the apartment he pays rent on."

Caitlin shrugged. "Works for me." Turning to Don, she answered his original question. "Yeah, I guess so. Charlie's orders."

Don looked at his brother, then shook his head. "I don't have time to sort this out now. I'll see you guys at home." He turned to leave.

"Don, wait!" Charlie hurried to follow him out the door. "Can you or David or Colby or someone go by CalSci and bring Caity's U-Haul home for her?"

"Sure," Don replied. "Leave the keys on my desk and let me know where she's parked and I'll get someone to help me."

"Thanks." Charlie slapped his brother on the shoulder as Don left for the armory. "C'mon, Caity, let's get you home."

When Don arrived home about three hours later, he was surprised to hear music floating through the house. His father was sitting in his favorite chair in the living room, eyes closed, Charlie at the dining room table with his computer, and Caitlin was at the piano.

"Hey, Dad," Don greeted his father softly, thinking he was asleep. "I'm home."

Alan opened his eyes. "Nice to see you, Donnie," he greeted. "Now be quiet—I'm listening."

Don nodded. "Okay. I brought Colby with me—he brought my SUV home so I could get Cait's U-Haul from CalSci." He gestured for his friend to take a seat at the dining room table while he headed to the refrigerator.

"Hey, Don, Colby," Charlie looked up from the syllabi he was typing up on his computer.

"Thanks for bringing my U-Haul, bro," Caitlin said, turning around to try to find Don.

"No problem, sis," Don replied, returning from the kitchen with a couple of beers. "Hey by the way, this is Colby. He brought my SUV back so I could bring your U-Haul, and decided to hang out for a bit. Colby's one of my agents. Colby, this is my little sister Caitlin," he introduced.

"Hi, Caitlin," Colby raised a hand in greeting.

Caitlin twisted her head around and gave him a nod and a smile. "Nice to meet you, Colby."

"What are you playing?" Colby asked, settling back in his chair, beer in hand.

"Bach," Charlie answered absentmindedly from his syllabi. "I tried to get her to go to bed, but clearly I have no control over her."

Caitlin chuckled from the piano. "He's right, on both counts. It's Bach's Prelude and Fugue in F minor," she answered Colby's question. "And Charlie told me to relax. This is relaxing. I haven't played in a week because I was driving out here, so it was the perfect way to unwind."

"She's been playing for almost forty minutes now," Alan commented from the living room, eyes still closed. "And I am very much enjoying it."

"Hey, speaking of pianos, what did you do with yours?" Don asked. Turning to Colby, he explained, "My mom set aside money for a piano as a graduation gift for Caity when she graduated from NYU a couple of years ago. Caity didn't get a chance to finish her degree before my mom died, so Dad kept saving until she actually graduated last summer. Dad bought her a brand-new Steinway baby grand that she had to keep in a storage unit because it wouldn't fit in her apartment." He chuckled at the mental picture.

"CalSci paid for it to be transported out here, so I can have it in my office," Caitlin answered, finishing the fugue and turning around on the piano bench to face the rest of her family. "That way I don't have to worry about finding a place big enough for it."

"So where does the musical ability come from?" Colby asked. "I mean, no offense, but none of you three seem to be exceptionally gifted when it comes to music." He gestured vaguely to Alan, Don, and Charlie.

"Mom," Charlie answered. "Mom was the one who loved music. She made us all take piano lessons; Caitlin was the only one who stuck with it. Don and I whined and pleaded until she let us stop, but Caitlin kept going."

"And going, and going," Don added. "Some days, it felt like all Caitlin did was play the piano."

"Only when I wasn't dancing," Caitlin pointed out, not pausing in her playing. "If I wasn't doing homework, it was always either piano or dancing."

"Dancing?" Colby questioned. "What kind?"

"Classical ballet, mostly," Caitlin said. "I also really enjoy tap, and I did a couple of years of competitive dance. But my heart is in ballet, and I usually go back to that."

"Since Mom made us play the piano, Dad said he had the right to make us all play a sport. I played baseball, obviously, Charlie was exempt by Mom's rules, and so Caitlin tried a bunch of stuff—soccer, cheerleading, gymnastics—before finally sticking with dance."

"Wow," was all Colby could manage.

Caitlin turned around and began to play another piece—Colby realized he knew the song, Beethoven's Fur Elise. Don turned his attention to Charlie and struck up a conversation about the upcoming schoolyear, Charlie's classload, and the FBI, among other things. Alan leaned back in his chair and closed his eyes, content to listen to the music.

Colby, however, was enthralled. He couldn't divert his ears from the music any more than he could divert his eyes from the brown-haired beauty at the piano. He watched Caitlin's hands as they danced over the keys, her eyes as she concentrated on playing the pieces from memory, looking at where her hands were but also where they were going.

Caitlin played for another hour or so. After Fur Elise, she switched to Brahms – a Hungarian Dance that started out slow and made both Charlie and Don look up in surprise when it suddenly sped up. Afterwards, one of her favorite Chopin waltzes. Charlie was getting tired by then, and requested Bach's Air as a last piece before he went to bed.

She busied herself with a slightly more technical piece after Charlie went to bed, playing several more Bach fugues. They were her favorite as far as math went—Bach's compositions were logical and mathematical, and she liked playing them only after she'd broken all the bits of it apart, examined them, and put them back together. She'd seen Don in her peripheral vision making motions to get ready to leave, but he needed to take Colby back to the FBI to get his car, and Colby was thoroughly entranced in the music.

Halfway through Brahms Variation on an Original Theme in D, Caitlin started yawning. It was a long piece, but she'd really needed to stretch her fingers. The call from CalSci had come just days before she'd began her cross-country journey, and it had been a long week without the piano. At a break in the music, Don stood, announcing softly that he probably needed to get going.

Caitlin was so tired, she didn't really remember her hands coming off the keys. She didn't remember saying goodbye to Colby and Don and heading upstairs to bed.

Colby remembered. All the way home, he remembered the sound of the music as it floated through the Eppes household, and although he was dead tired, he actually turned his clock radio to a classical music station as he readied for bed, and was asleep within minutes, dreaming of the blue-eyed, brown-haired little sister of Don and Charlie Eppes who had intrigued him all evening.

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><p><strong>Feedback is lovely. Also, I'm taking suggestions for oneshots. I've got major drama events covered, but any kinds of minor fightsfluff/whatever between Colby and Caitlin, send your ideas my way! Credit will be given wherever credit is due :)  
><strong>

Also, I made a Spotify playlist of all the pieces mentioned in this chapter. You can find it on this story's blog, symphonyinc7 . wordpress . com

**xo **


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